Optical distance measuring sensor and self-propelled cleaner

• US 20060050263A1
• Filed: 06/22/2005
• Published: 03/09/2006
• Est. Priority Date: 06/25/2004
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Mizuo, Kazuhiro, Yamaguchi, Akifumi, Kawanishi, Shinya, Fujikawa, Atsuo
• Granted Patent: US 7,119,887 B2
• Time in Patent Office: Days
• US Class Current: 356/5.10
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
• CPC Class Codes: G01S 7/481 Constructional features, e.g. arrangements of optical elements
• CPC Class Codes: G01S 7/4814 of transmitters alone

Abstract

An optical distance measuring sensor has a plurality of light-emitting elements (51-55), a light-emitting lens (1), a photodetector (4) having a light-receiving surface, a light emission driving part (31) to sequentially drive the light-emitting elements, and a distance signal outputting part (31). Light emitted from each light-emitting element passes through the light-emitting lens, then is reflected by an object (32) to be detected, and then gets incident on the light-receiving surface of the photodetector, which outputs a signal corresponding to a position of the incident light in the light-receiving surface. Upon receipt of the signal, the distance signal outputting part outputs a distance signal representing a distance to the object.

Claims

1. An optical distance measuring sensor comprising:

a plurality of light-emitting elements that emit light;

one lens that transmits light emitted from the plurality of light-emitting elements;

a photodetector having a light-receiving surface on which light passed through the lens and reflected on an object to be detected is incident, the photodetector outputting a signal corresponding to a position of the incident light in the light-receiving surface;

a light emission driving part that drives the plurality of light-emitting elements; and

a distance signal outputting part that receives a signal from the photodetector and outputs a distance signal representing a distance to the object to be detected.

2. The optical distance measuring sensor as claimed in claim 1, which has a detection range determined by a number of the light-emitting elements.

3. The optical distance measuring sensor as claimed in claim 1, which has a viewing angle determined by a distance between the light-emitting elements.

4. The optical distance measuring sensor as claimed in claim 1, which has a detection range determined by a distance between the light-emitting elements and the photodetector.

5. The optical distance measuring sensor as claimed in claim 1, further comprising:

a light-permeable first sealing portion that seals the plurality of light-emitting elements; and

a non-light-permeable second sealing portion that covers a portion of a surface of the first sealing portion other than a portion at which light paths extending from the plurality of light-emitting elements to the lens meet the surface of the first sealing portion.

6. The optical distance measuring sensor as claimed in claim 5, wherein

the first sealing portion has lens-shaped portions through which light beams from the corresponding light-emitting elements go outward.

7. The optical distance measuring sensor as claimed in claim 1, comprising:

a timing signal outputting part that outputs a timing signal having a prescribed cycle,

wherein the light emission driving part drives a selected one of the light-emitting elements to emit light in synchronization with the timing signal, and

wherein the distance signal outputting part outputs the distance signal in synchronization with the timing signal.

8. The optical distance measuring sensor as claimed in claim 7, comprising:

an initialization signal outputting part that outputs an initialization signal at a timing for switching the light emission among the light-emitting elements,

wherein upon receipt of the initialization signal, the timing signal outputting part initializes the output of the timing signal, and

wherein upon receipt of the initialization signal, the light emission driving part switches the light-emitting element that should be driven to emit light among the light-emitting elements.

9. The optical distance measuring sensor as claimed in claim 1, comprising:

a casing which is formed of a conductive material and in which at least the light-emitting elements, the photodetector, the light emission driving part and the distance signal outputting part are contained.

10. The optical distance measuring sensor as claimed in claim 9, comprising:

a board which has a grounding electrode and on which at least the light-emitting elements, the photodetector, the light emission driving part and the distance signal outputting part are mounted,

wherein the grounding electrode of the board is electrically connected to the casing.

11. The optical distance measuring sensor as claimed in claim 1, comprising:

a pyroelectric sensor.

12. A self-propelled cleaner comprising the optical distance measuring sensor claimed in claim 1.